3-methyl-4,4-dialkoxy-1-butyraldehyde as a pharmaceutical chemical intermediate has favorable application prospect. The molecular structure thereof is special and has two kinds of groups such as aldehyde and acetal, both of them are especially suitable for construction of a double bond system. Recently it has been reported from CN201010189861.0 by Runbo Shen, etc. that a new preparation method of lycopene by using 3-methyl-4,4-dialkoxy-1-butyraldehyde as a raw material is a typical example as a pharmaceutical intermediate, and it takes the advantages of simple process route, easy operation, low cost, and great commercial value.
At present it is less reported on synthesis method of 3-methyl-4,4-dialkoxy-1-butyraldehyde, and currently there are mainly two methods:
A: 2-methyl-propylene dimethyl acetal (3) as a raw material, condenses with hydrogen and carbon monoxide to obtain the product (1) in the presence of catalyst and high pressure, the reaction equation is described as follows:

B: It was reported by Schmid etc. that 2-methyl-4-(N,N-diethyl)-2-butylene dimethyl acetal (4) as a raw material, rearranges to 2-methyl-4-(N,N-diethyl)-3-butylene dimethyl acetal (5) in the presence of catalyst of ruthenium and phosphorus complexes, and then hydrolyzes to obtain 3-methyl-4,4-dimethoxy-1-butyraldehyde (1A). The reaction equation is described as follows:

Both of the two process routes are simple, but it requires using hydrogen and carbon monoxide in the presence of catalyst and high pressure in the method A. It results in production equipments bringing about difficult and dangerous synthesis; 2-methyl-4-(N,N-diethyl)-2-butylene dimethyl acetal (4) of method B as a raw material is difficult to acquire and synthesize; and some expensive and complicated catalysts are used in the two processes. Both of these makes industrialization difficult.